Just took a quick look, and the 2.6L puts out the most torque at 3000rpm, and that is now accessible at freeway speeds in 4th and 5th gear due to the slightly larger tires. I think that's why I'm seeing what I perceive as better performance with the 31's.

http://www.4x4wire.com/mitsubishi/tech/engine_specs/

That's my story and I'm stickin' to it ;-)

1987 Raider, 346K miles and going strong -31" tires, otherwise stock.
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